Europace (2002) 4, 317–324 doi:10.1053/eupc.2002.0239, available online at http://www.idealibrary.com on

Interatrial septum pacing avoids the adverse effect of interatrial delay in biventricular pacing: an echo-Doppler evaluation Maria Cristina Porciani, Alessandra Sabini, Andrea Colella, Antonio Michelucci, Nicola Musilli, Paolo Pieragnoli and Luigi Padeletti Institute of Internal Medicine and Cardiology, University of Florence, Florence, Italy

Aims Biventricular pacing (BVP) can improve haemodynamics in patients with dilated cardiomyopathy (DCM) and left bundle branch block by reducing interventricular delay (IVD). Since in DCM interatrial delay (IAD) and IVD frequently coexist, the aim of this study was to test the hypothesis that IVD reduction associated with IAD produces an imbalance between the programmed right atrioventricular (AV) delay and the effective AV delay on the left, and that interatrial septum pacing (IASP) combined with BVP overcomes this adverse effect. Methods and Results IAD, IVD, left and right mechanical atrioventricular delay (L-RMAVD) were measured by echo-Doppler in 29 patients with BVP: 17 patients (Group A) had the atrial lead in the right atrial appendage, 12 patients (Group B) who experienced paroxysmal atrial fibrillation had the atrial lead on the interatrial septum. In Group A, LMAVD was significantly shorter than RMAVD

Introduction In patients with chronic heart failure left bundle branch block (LBBB) may worsen left ventricular systolic dysfunction through asynchronous ventricular contraction and relaxation[1,2]. Biventricular pacing (BVP) has been introduced in order to improve haemodynamics by reducing interventricular delay (IVD) and restoring ventricular synchrony. Preliminary studies report promising results: quality of life, distance walked in 6 min, New York Heart Association (NHYA) class, peak VO2, left ventricular geometry and ejection fraction (EF) have all improved[3–6]. Manuscript submitted 22 August 2001, and accepted 29 March 2002. Correspondence: Maria Cristina Porciani, MD, Institute of Internal Medicine and Cardiology, University of Florence, Florence, Italy, Viale Morgagni 85, 50134 Florence, Italy. Tel: + 39 055 4277634; Fax: + 39 055 4378638; E-mail: [email protected] 1099–5129/02/030317+08 $35.00/0

(17224 vs 20724 ms, P